EP2183422B1 - Method for the treatment of washing and programme-controlled washing machine suitable therefor - Google Patents

Description

The invention relates to a method for treating laundry in a program-controlled washing machine and to a washing machine which is particularly suitable for carrying out this method.

In a known washing process, the laundry to be washed only with a wash liquor, also referred to as "liquor" comprising treated an amount of water sufficient that the laundry to be washed is saturated with water and a remaining, the smallest possible free fleet , generally 2 to 3 liters, an exchange between the heating and the wash liquor for heating the wash liquor and the laundry allows. This is ensured by a suitable method for controlling the water level in the drum and adjusting the amount of water to the suction capacity of the laundry. The free liquor results after deduction of the amount of water bound in the laundry of the amount of water filled in the washing machine. Cotton fabric binds about 200% of its own weight, so that a load of 6 kg of cotton fabric binds about 12 l of water.

DE 4 104 450 A1 discloses the features of the preamble of claims 1 and 10.

In the DE 10 2004 039 662 A1 a program-controlled washing machine with a wetting process is described, which can be adjusted to the required amount of water in a tub in a tub rotatably mounted about a non-vertical axis laundry drum by means of a water supply system and a control device, the supply of water in the tub is timed and the Wetting process in as many phases (Ph1 to Ph3) is divided, as quantity levels (small, medium, large) are provided for the laundry to be treated.

The energy consumption of a washing machine is essentially determined by the energy required for the heating of the water. A reduction in the amount of water in the washing machine would therefore be desirable, in particular a reduction in the amount of free liquor. However, the heat transfer from the heater to the laundry must be effected by the free liquor. A further reduction of the fleet and thus a reduction in energy consumption are thus difficult to achieve.

The object of the invention is therefore to provide a method for treating laundry in a program-controlled washing machine, in which energy can be saved compared to known methods.

The object is also to show a suitable for carrying out this process washing machine.

According to the invention, these objects are achieved by a method having the features of patent claim 1 and by a washing machine having the features of patent claim 10. Advantageous embodiments of the invention are listed in the respective dependent claims. Preferred developments of the method according to this preferred developments of the washing machine and vice versa, although this is not set out in detail herein.

1. a) Benetzen einer Beladungsmenge (a1) an Wäsche mit einer Wassermenge (a2), die geringer ist, als die zur Sättigung der Wäsche mit Wasser erforderliche Menge (a3) an Wasser ("Sättigungsmenge");
2. b) Rotieren der Trommel mit einer Drehzahl U₁, die größer als eine Anlegedrehzahl U_A der Wäsche ist, bis ein Raum zwischen dem Laugenbehälter und der Trommel mit Schaum gefüllt ist und der Schaum in das Innere der Trommel gelangt; und
3. c) Einschalten der Heizeinrichtung und Heizen des Schaums und damit der Wäsche.

The invention thus relates to a method for the treatment of laundry with an aqueous wash liquor in a program-controlled washing machine with a liquor drain system arranged at the bottom of a tub with a drain pump, a heater, a sensor for determining the amount of a liquid in the tub or a foam, wherein a Sensor signal is tracked during the process, and a drum, and wherein the method comprises the following steps:

1. a) wetting a loading amount (a1) of laundry having an amount of water (a2) which is lower than the amount (a3) of water required to saturate the laundry with water ("saturation amount");
2. b) rotating the drum at a speed U ₁ which is greater than an application speed U _{A of} the laundry until a space between the tub and the drum is filled with foam and the foam enters the interior of the drum; and
3. c) switching on the heater and heating the foam and thus the laundry.

The application speed U _{A of} the laundry is the rotational speed of the drum at which the laundry can rest against an inner wall of the drum, for example a speed in the range of 300 to 500 revolutions per minute.

For example, with a loading amount (a1) of 6 kg with cotton cloth laundry, a water amount (a2) of 10 liters could be used.

For cotton fabric, the saturation amount (a3) of water is about twice a loading amount (a1). For synthetic fibers, which can absorb water to a lesser extent, the saturation amount (a3) may be significantly lower. The values for the saturation amount (a3) are known per se, so that the amount of water (a2) can be specified in a wash program.

Here, if necessary, the loading amount (a1) or the type of laundry to be treated, or both, can be determined by a measure known per se.

To determine the loading quantity (a1), for example, in method step a), a hydrostatic pressure p measured with the aid of the sensor can be compared with the filled-in amount of water. The laundry in the drum absorbs water, which therefore can not contribute to an increase in the hydrostatic pressure. By comparing the measured hydrostatic pressure and the accumulated amount of water - the absolute values and their temporal change - with corresponding values stored in the program control of a washing machine for the moisture content of laundry, the amount of laundry (load (a1)) and its degree of wetness (degree of wetting) determine. As a result, the duration of wetting in step a) can be matched very precisely to the predetermined amount of laundry. In general, water is filled until a predetermined threshold value p ₁ for the hydrostatic pressure p and a predetermined threshold value (Δp / Δt) ₁ for the time gradient of the hydrostatic pressure p is reached. Thus, in general, a program for the inventive method sufficient wetting of the laundry cost is signaled to a program, so that step a) is completed and step b) can be started.

According to the invention, it is preferred that the amount of water (a2), based on the weight of the loading amount (a1), is 90 to 170%, particularly preferably 130 to 150%.

In step b) of the process, a portion of the wash liquor is spun off and conveyed into a gap between the drum and the tub. If the amount of water increases so much that the rotating drum dips into the wash liquor, the wash liquor is beaten to foam due to the high mechanical action of the drum. As a result, the volume of the wash liquor can increase so much that the entire space between the drum and the tub is filled. The foam is then introduced through a front gap between the drum and the tub in the Interior of the drum crowded. There, the foam is subjected to the centrifugal force of the drum, pressed through the laundry and transported back into the space between the drum and the tub. This forms a cycle of the laundry enforcing foam.

The complete filling of the tub with foam can be determined by suitable sensors. As a sensor for determining the amount of a liquid in the tub or a foam whose sensor signal is tracked during the process, a conventional sensor can be used for the determination of the water level. Such a sensor generally measures a hydrostatic pressure p and / or the time gradient (Δp / Δt) _{1 of} the hydrostatic pressure p. Completely filled with foam generally shows a sudden increase in pressure on the sensor. This circumstance can be taken as a reason for the introduction of step c).

• d) bei Erreichen einer vorgegebenen Waschtemperatur T_w reversierendes Betreiben der Trommel mit einer Drehzahl U₂, die kleiner als die Anlegedrehzahl U_A ist.

In a preferred embodiment, the method according to the invention additionally and following step c) comprises a step

• d) upon reaching a predetermined wash temperature T _w reversing operation of the drum at a speed U ₂ , which is smaller than the application speed U _A.

The speed U ₂ can vary within wide ranges. Preferably, a speed U ₂ in the range of 30 to 80, in particular 40 to 60, for example 50 revolutions per minute is used. Here, by the walking and rubbing of the laundry items together and the action of the wash liquor, in particular the dirt present in the laundry is detached from the fibers.

• e) Auffüllen des Laugenbehälters mit Wasser in einer Menge, die ausreicht, dass zusätzlich zur Sättigungsmenge (a3) eine Menge (a4) an freier Flotte vorhanden ist, die ausreicht, dass ein Raum zwischen dem Laugenbehälter und der Trommel an einem unteren Ende der Trommel mit Wasser gefüllt ist und die Wäsche benetzen kann.

The method according to the invention preferably comprises a step in addition to step d) and subsequent thereto

• e) filling the tub with water in an amount sufficient to provide, in addition to the saturation amount (a3), an amount (a4) of free liquor sufficient to allow a space between the tub and the drum at a lower end of the drum filled with water and can wet the laundry.

In general, in this case, a quantity of water of 3 to 8 liters, for example 5 liters, is charged at a loading amount (a1) of 6 kg. The then total present Amount of water can correspond to the amount of water of a conventional washing program.

• f) reversierendes Betreiben der Trommel mit einer Drehzahl U₂, die kleiner als die Anlegedrehzahl U_A ist.

In a particularly preferred embodiment, the method comprises a step in addition to steps a) to e) and then to step e)

• f) reversing operation of the drum at a speed U ₂ , which is smaller than the application speed U _A.

Due to the mechanical action due to the reversing operation of the drum, the laundry is flooded with the wash liquor. The dissolved dirt can be rinsed out and transferred to the wash liquor.

In a particularly preferred embodiment of the method according to the invention in step c) upon reaching a predetermined temperature T _Z , which is less than the wash temperature T _W (for example 30 or 40 ° C), the heating is interrupted and the drum at a speed U ₂ , which is smaller than the application speed U _A , reversing operated. This embodiment is particularly advantageous in the case of protein-containing contaminants, since in this way burning-in of the contamination can be prevented. Such a phase is also called bio-enzyme phase.

• g) Rotieren der Trommel mit einer Drehzahl U₁, die größer als eine Anlegedrehzahl U_A der Wäsche ist,

durchgeführt.In a further preferred embodiment of the method according to the invention, in which step d) is carried out, a step is performed in step d) at least once as an interruption of step d)

• g) rotating the drum at a speed U ₁ which is greater than an application speed U _{A of} the laundry,

carried out.

In this case, the drum is preferably rotated during a period of 60 seconds to 3.5 minutes, in particular 90 to 150 seconds, for example 120 seconds, with a rotational speed U ₁ which is greater than an application speed U _{A of} the laundry. The speed U ₁ may be, for example, 250 to 600 revolutions per minute, in particular 300 to 500 revolutions per minute. By step g) in particular a redistribution of the wash liquor is effected. In step g), another heating with the heating device could also take place.

At the end of step f), the washing process is generally completed.

In the further course of the process, the laundry can then be rinsed and spun as in a conventional washing program.

The invention also relates to a washing machine with a program control for controlling the program flow, a rotatably mounted in a tub drum, one at the bottom of the tub arranged Laugenablaufsystem with a drain pump, a drive motor for the drum, a heater, a sensor for determining a quantity of in the tub liquid or a foam, and switching means for rotating and stopping the drum, wherein the switching means and the sensor are adapted to carry out the method according to the invention described above.

The invention has numerous advantages. When carrying out the process according to the invention, a significantly smaller amount of water is heated compared to conventional processes. As a result, a significant saving of energy is possible.

An embodiment of the invention will be described below with reference to the FIG. 1 explained.

FIG. 1 Figure 3 is a schematic representation of the parts of a washing machine that are relevant to the following explanation in which a method as described herein can be performed. Other embodiments are conceivable. The washing machine of the FIG. 1 embodiment shown has a tub 1, in which a drum 2 is rotatably mounted and can be operated by a drive motor 14. According to recent findings for the ergonomics in dealing with such washing machines, the axis of rotation 3 of the drum 2 from the horizontal by a small angle (eg 13 °) directed forwardly upwards so that you have easier access and insight into the interior of the drum 2 , By this arrangement, in conjunction with specially shaped Wäschemitnehmern 4 and 5 Schöpfeinrichtungen for the wash liquor 6 on the inner surface of the drum shell also an intensification of the flooding of the laundry 7 with wash liquor and foam and a reduction of the free liquor is achieved.

The foam formed in step a) of the process fills in particular a space between the drum 2 and the tub 1.

In the preferred step e) water is introduced in an amount sufficient that a space between the tub 1 and the drum 2 at a lower end of the drum is filled with water and can wet the laundry. This means for the embodiment in FIG. 1 in that the water in the tub 1 extends at least to the lowest point of the drum 2 and the laundry contained therein.

The washing machine also has a liquor inlet system comprising a water connection fitting for the domestic water network 8, an electrically controllable valve 9 and a supply line 10 to the tub 1, which may optionally also be guided via a Waschmitteleinspüleinrichtung ("Einspülschale") 11, from which the feed water Can transport detergent into the tub. In addition, in the tub 1, a heater 13. The valve 9 as well as the heater 13 can be controlled by a control device ("program control") 12 in response to a program flowchart, the to a time program and / or to the achievement of certain measurements of Parameters such as liquor level, liquor temperature, speed of the drum 2, etc. may be bound within the washing machine. 15 means a sensor for measuring the hydrostatic pressure p in the tub 1.

Claims (10)

1. Method of treating a load quantity (a1) of laundry with an aqueous washing solution in a program-controlled washing machine with a solution drain system, which is arranged at the base of a solution container (1), with a solution pump, a heating device (13), a sensor (15) for determining a quantity of a liquid present in the solution container (1), the sensor signal of which sensor is tracked during the method, and a drum (2), characterised by the steps of

   a) wetting the laundry with a water quantity (a2) smaller than the quantity (a3) of water required for saturation of the laundry with water, i.e. the "saturation quantity";

   b) rotating the drum (2) at a rotational speed U₁, which is higher than a spreading rotational speed U_A of the laundry, until a space between the solution container (1) and the drum (2) is filled with foam and the foam passes into the interior of the drum (2); and

   c) switching on the heating device (13) and heating the foam and thus the laundry.
2. Method according to claim 1, characterised in that it comprises, subsequently to step c), a step of

   d) carrying out reverse operation of the drum (2) at a rotational speed U₂, lower than the spreading rotational speed U_A when a predetermined washing temperature T_W is reached.
3. Method according to claim 2, characterised in that it comprises, subsequently to step d), a step of

   e) filling with water in an amount which suffices so that additionally the saturation quantity (a3) a quantity (a4) of free solution is present sufficient for a space between the solution container (1) and the drum (2) at a lower end of the drum (2) to be filled with water and for the laundry to be able to be wetted.
4. Method according to claim 3, characterised in that it comprises, subsequently to step e), a step of

   f) carrying out reverse operation of the drum (2) at a rotational speed U₂ lower than the spreading rotational speed U_A.
5. Method according to any one of claims 1 to 4, characterised in that the water quantity (a2) referred to the weight of the load quantity (a1) is 90 to 170%.
6. Method according to claim 5, characterised in that the water quantity (a2) referred to the weight of the load quantity (a1) is 130 to 150%.
7. Method according to any one of claims 1 to 6, characterised in that in step c) on reaching a predetermined temperature T_Z lower than the washing temperature T_W the heating is interrupted and reverse operation of the drum (2) is carried out at a rotational speed U₂ lower than the spreading rotational speed U_A.
8. Method according to claim 2, characterised in that in step d) a step g) of rotating the drum (2) at a rotational speed U₁ higher than a spreading rotational speed U_A of the laundry is carried out at least once as an interruption of the step d).
9. Method according to claim 8, characterised in that the drum (2) is rotated during a time period of 60 seconds to 3.5 minutes at a rotational speed U₁ higher than a spreading rotational speed U_A of the laundry.
10. Washing machine with a program control (12) for controlling the program sequence, a drum (2) rotatably mounted in a solution container (1), a solution drain system, which is arranged at the base of the solution container (1), with a solution pump, a drive motor (14) for the drum, a heating device (13), a sensor (15) for determining a quantity of liquid or foam present in the solution container (1), and switching means (9, 12, 14) for rotating and stopping the drum, characterised in that the switching means (9, 12, 14) and the sensor (15) are arranged for performance of a method for treating a load quantity (a1) of laundry with an aqueous washing solution, characterised by the steps of

    a) wetting the laundry with a water quantity (a2) smaller than the quantity (a3) of water required for saturation of the laundry with water, i.e. the "saturation quantity";

    b) rotating the drum (2) at a rotational speed U₁, which is higher than a spreading rotational speed U_A of the laundry, until a space between the solution container (1) and the drum (2) is filled with foam and the foam passes into the interior of the drum (2); and

    c) switching on the heating device (13) and heating the foam and thus the laundry.

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